cat-o'-nine-tails vs thong

cat-o'-nine-tails

noun
  • A similarly constructed leather nine-tail whip, as used in British penal colonies and certain armies. 

  • A scourge (multi-tail whip) having nine, often knotted, whipcords, formerly used for flogging as naval punishment. 

thong

noun
  • The largest section of a bullwhip constructed of many straps of braided leather. 

  • A strip of leather. 

  • An item of footwear, usually of rubber, secured by two straps which join to pass between the big toe and its neighbour. 

  • An undergarment or swimwear consisting of very narrow strips designed to cover just the genitals and nothing more. 

How often have the words cat-o'-nine-tails and thong occurred in a corpus of books? (source: Google Ngram Viewer )